The best mech game ever made.
The controls for this mech game are excellent; it feels like how I imagine controlling a mech would really be. Intuitive and clumsy at the same time, but with a weird sort of finesse, that comes with many, many hours of practice.
The missions range from very short to very long, with hidden weapons and equipment spread through many of the levels.
Where this game truly shined for me was in the mech customization. Customizing the mech, trying new ideas, changing the color or pattern, was all very easy, and highly enjoyable. Something I find lacking in the later versions of Armored Core.
For about 15 years this game has kept me happily coming back for more, and I expect it to keep me coming back for another 15 more.